Power-transmission belt.



J. E. RHOADS.

POWER TRANSMISSION BELT.

APPLICATION FILED APR.19, 1912.

' Patented June 25, 1912.

Jw vz/zagwizzww JOSEPH EDGAR RHOADS, 0F WILMINGTON, DELAWARE.

POWER-TRANSMTSSIDN BELT.

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Specification of Letters Patent.

- Patented June 25, 1912.

Application filed April 19, 1912. Seria1 No. 691,813.

Transmission Belts, of which the following is a specification.

One ob'ect of my invention is-to provide a belt. such as that commonlyused for transmitting power between the driving and the driven membersof a motor cycle or other driven vehicle, which shall be more efficientthan those at present known to the art by reason of a novel arrangementofv parts whereby it shall present a maximum engaging surface to thesmall pulley as well as to the larger pulley around which it passes.

I further desire to provide a power transmission belt built up of anumber of sections and substantially trapezoidal in cross section whichshall have such a form that its edges will continuously engage the sidewalls of the smaller of the two pulleys with which it is customarilyused as well as the walls of the groove of the larger pulley, in

order to prevent the slipping which fre quently occurs on the smallerpulley.

These objects and other advantageous ends I secure as hereinafter setforth, reference being had to the accompanying drawings in which,

Figure l is a vertical section of a substantially straight run of a beltconstructed according to my invention; Fig. 2 is an inverted plan of apart of the belt shown in Fig. 1; Figs. 3and 4 are transverse sectionson' the lines a-a and b-b respectively of Fig. 2; and Fig. 5 is asection taken in the central plane of the belt, illustrating it with itsseveral parts in the positions occupied while passing around the smallerof the two pulleys with which it is customarily used.

In the above drawings, 1 and 2 represent the two outer layers of thebelt which are preferably cemented or otherwise connected so as toformin effect a single endless band 3, constituting the body of the belt.This body is preferably trapezoidal in cross section and has mountedupon its inner or narrower face a series of similarly shaped blocks 4also trapezoidal in cross section and curved in longitudinal outline asindicated in Figs. 1 and 5. The summits or narrow tops of these curvedblocks or pieces are joined by a continuous band 5 connected to them andto the body of the belt by a series of rivets (3, one of which passescentrally through each of said blocks. It is to be especially noted thatthe band 5 varies in width as shown in Fig. 2, being narrowest oppositeeach of the rivets and thereafter gradually broadening to an amountdepending on theshape of the groove and the diameter of the smaller ofthe two pulleys on which the belt is to be used. \Vitl this constructionand arrangement of parts the belt at each of the rivets 6 has atrapezoidal cross section as shown in Fig. 3, which is similar in formand dimensions to the pulley grooves in which the belt operates. As isshown in Fig. 5, when the belt passes around a relatively small diameterpulley, the inner band or layer 5 is caused to assume the corrugatedform illustrated in Fig. 5, and if said band were of uniform width, itis obvious that its edges could engage the walls of the groove in thesmall pulley for limited portions only thereof immediately adjacent therivets 6, for the reason that the outwardly curved parts of said bandbetween said rivets, being farther from the center of the pulley, wouldnot be of sufficient width to engage the wall of the groove. However, ifthis inner band he made as illustrated in Fig. 2, so as to have anincreased width between the blocks 4 and the rivets, then whenit isgiven the corrugated form shown in Fig. 5 in passing around a smalldiameter pulley, the increased width is sufiicient to cause its edges tocontinuously grip the walls of the pulley groove from points oppositeone rivet and its block to similarpoints opposite the next block. Thereis thus provided a materially increased engaging surface between thesmall diameter pulley and the belt passing around the same andconsequently a greater amount of power can be transmitted from saidpulley to a belt of given dimensions. It will be understood that theleather or other material of the band 5 is sufliciently flexible toproperly accommodate itself to the shape of the groove of the largerpulley, although owing to the blocks 4 it'will be held in proper form tocontinuously engage the wall of the smaller pulley groove as heretoforedescribed.

1. The combination in a power transmission belt of an endless bodyportion; a series of blocks mounted on one face of said body portion anda band extending between and connecting the summits of said blocks; saidband varying in width between each pair of blocks.

2. The combination in a power transmission belt of a body portion havinga series of blocks on its inner face; and a structure mounted adjacentsaid blocks and formed to have its edges engage the divergent walls of apulley groove when in a corrugated form.

v 3. The combination in a power transmission belt of a body portion; aseries of projections mounted on the inner face thereof; and a bandextending between said projections; said belt being substantiallytrapezoidal in section adjacent each projection and the band increasingin width from each rivets res ectivelypassingthrough the body, the andand the blocks; saidband increasing inwidth-from a minimum adjacent eachrivet to a maximum midway between each pair of rivets.

In testimony whereof, I have signed my name tothis specification, in thepresence of two subscribin witnesses.

J OS EDGAR RHOADS.

Witnesses;

WILLIAM E. BRADLEY, J 0s. H. Knnm.

ace thereof; anlendless' ination in a power transmis-

